Calixtus

Calixtus, the name of three Popes. Calixtus I. was Bishop of Rome from 217 to 224, when he was martyred. He is said to have been originally a slave. Calixtus II., previously Guido, Archbishop of Vienne, was elected pope in 1119, succeeding Gelasius II., who had been expelled. Calixtus III. was chosen in 1168 as anti-pope to Paschal III. The title Calixtus III. was also assumed by Alfonso Borgia, elected pope 1455.